2 layers16.9 × 14.4 mm

Rs485-ch340e
TG9541/rs485-ch340e
A small CH340E based configurable RS485 or TTL 2/3-wire USB dongle
17 parts15MIT
KiCad boards from 1 GitHub repository tagged “2-wire”, the most starred first; open any of them in PCBKit.

TG9541/rs485-ch340e
A small CH340E based configurable RS485 or TTL 2/3-wire USB dongle